The number of coronavirus infections has spiked, Chinese officials announced Saturday.

The pneumonia-causing illness that infects the respiratory tract was responsible for at least 56 deaths in Central China, with 15 new fatalities as of Saturday, and more than 1,975 cases, with approximately 1,000 new cases identified by Chinese health officials. On Saturday, the trade association of Chinese travel agencies also said that it would suspend overseas tour groups and flight/hotel vacation packages for Chinese citizens, effective Monday.

The outbreak spread rapidly over the last seven days. It has infected people in Hong Kong, Australia, Malaysia, Thailand, France, Japan, Taiwan, Vietnam, Singapore, South Korea, Macao and Nepal. There have also been three confirmed cases in the U.S., the Centers for Disease Control and Prevention said. It is believed to have originated in Wuhan, likely at a food market. On Saturday, the U.S. State Department ordered the evacuation of all U.S. personnel at the Consulate in Wuhan.

The spread of the pneumonia-causing virus was likely helped by travel related to China’s Lunar New Year holiday, which began Friday. This week, officials in Wuhan, a city with 11 million residents, closed the area’s outgoing airport and railway stations, and suspended all public transport. Chinese officials have since expanded that ban 16 surrounding cities with a combined population of more than 50 million people, including Huanggang, a neighboring city to Wuhan with 7.5 million people.

Hong Kong’s city leader Carrie Lam declared a state of emergency and said all primary and secondary schools would close until Feb. 17, two more weeks in addition to next week’s Lunar New Year holiday, the Associated Press reported, adding that the city’s marathon scheduled for Feb. 9, which typically attracts 70,000 participants, was also cancelled. Most of the cornavirus fatalities were older patients, although a 36-year-old man in Hubei died earlier this week, the AP added.

A new study published in the Lancet identified five of six family members with coronavirus. “From Jan 10, 2020, we enrolled a family of six patients who travelled to Wuhan from Shenzhen between Dec 29, 2019 and Jan 4, 2020. Of six family members who travelled to Wuhan, five were identified as infected with the novel coronavirus. Additionally, one family member, who did not travel to Wuhan, became infected with the virus after several days of contact with four of the family members.”

The study said that the evidence thus far shows the coronavirus is spreading from person to person, rather than exclusively from animals or infected food, and can be transmitted in social, family and even hospital environments. Perhaps more alarmingly, it is also now being spread by people who have not been to Wuhan, it added. “This is a novel coronavirus, which is closest to the bat severe acute respiratory syndrome (SARS)-related coronaviruses found in Chinese horseshoe bats.”

Quentin Fottrell

Quentin Fottrell is MarketWatch’s personal-finance editor and The Moneyist columnist for MarketWatch. You can follow him on Twitter @quantanamo.